Fresh engine, wiped cam? Tick? (new pics added)

Did you roll each pushrod on a piece of glass to check for straitness?

I can't stress the point of the pushrod length being critical enough. This may be the cause. That would put the cause in your builders lap. If you can pull the cam (you will have to remove the radiator and grill), you can do a poor mans cam chack with dial calipers. All lobes should be slightly (.003" or so) taller at the aft edge of the lobe when compared to the forward edge of the same lobe. This is incorrect...Small Block Mopar's have alternating lobes...8 machined fwd...8 machined aft....oil pump drive gear provides cam fwd thrust.

Since you have the intake off, rotate the engine over by hand so that you are on the base circle of the cam and then install the rocker arm shaft with just those two rockers. Keep the rest of the rockers and parts in order and set aside. as you tighten the rocker shaft down (use the two hold downs, 1 on either side of the cylinder you're checking), pay attention to the lifters. Watch the lifters as you tighten the bolts down. They should only be preloaded about .025". That is 1/4th of 1/10th of an inch. It's not much.

If it is more than around .040", it is probably too much.
You can fix the preload issue cheaply with rocker shaft shims, but that won't fix your cam and lifters.